Over the past several years, air pollution monitoring inKeene has identified periods when the air contains unhealthyconcentrations of fine particulate matter (PM2.5).

When this occurs, people may experience difficult breathing,aggravated asthma or heart conditions. Unlike the summertimesmog events that much of the state experiences, mostof these events occur during the cold weather months whenpeople expect clean air.

In 2007, NHDES began continuous PM2.5 monitoring in Keeneto better understand the situation and found that PM2.5 concentrationsspiked at nights when the winds went calm and then dropped the next day when the winds picked up again.

This was significant because it eliminated upwind areasfrom being the primary cause of this problem. Keene hasbenefited from a wood stove changeout program and an outreachand educational program to help residents burn wood more cleanly.

However, NHDES is still seeing some unhealthyconcentrations; is wood burning the primary cause of thisair pollution problem? When the air pollution monitoringfilters returned to our labs smelling of wood smoke, we weregiven a clue.

During the winter of 2012-2013, NHDES conducted a specialmonitoring study designed to better understand the rolethat residential wood burning plays in the city’s high winterair pollution. NHDES enhanced its Keene monitoring stationto collect continuous PM2.5, sulfur dioxide (SO2), carbonmonoxide (CO), black carbon, levoglucosan, and several tracemetals. These pollutants were selected because their presence,absence, and how their concentrations vary in relationto other pollutants helps to identify the nature of the pollu-tion sources. Levoglucosan was specifically selected becauseit is an organic compound that is uniquely formed during theburning of wood cellulose. If it is measured in the air, woodwas burned. CO and black carbon are also good indicators ofwood burning, but there are other sources in the area thatcreate these pollutants. SO2 and the trace metals were selectedto help identify the roles of local coal, oil, industry andautomotive emission sources.

The study found a very strong relationship between thelevoglucosan and PM2.5 concentrations at the Keene station,signifying that wood burning is the primary cause of thePM2.5 concentrations. In addition, there were indicationsof oil and coal burning; probably also related to residentialheating, but these sources play only a minor role in Keene’sPM2.5 levels. Automotive and local industry were not identifiedas significant PM2.5 sources and while regional transportcan contribute to unhealthy air in the city, it is the localresidential wood burning that dominates these air pollutionevents.

• The Surgeon General has determined that there is no safe level of exposure to ambient smoke!

• If you smell even a subtle odor of smoke, you are being exposed to poisonous and carcinogenic chemical compounds!

• Even a brief exposure to smoke raises blood pressure, (no matter what your state of health) and can cause blood clotting, stroke, or heart attack in vulnerable people. Even children experience elevated blood pressure when exposed to smoke!

• Since smoke drastically weakens the lungs' immune system, avoiding smoke is one of the best ways to prevent colds, flu, bronchitis, or risk of an even more serious respiratory illness, such as pneumonia or tuberculosis! Does your child have the flu? Chances are they have been exposed to ambient smoke!